There has recently become available in the United States a television service utilizing a Digital Satellite System (DSS) to provide direct satellite to user transmission. The satellites are of a power sufficient to permit the use of antennas as small as 18 inch user mounted antenna dishes. A large number of channels are broadcast including non-premium, premium, and pay-per-view (PPV) access. PPV movies or video films are available starting as often as every 30 minutes for a fixed price per viewing.
A TV set top receiver translates the DSS stream into an analog signal fed to the television receiver. For pay-per-view and automatic billing services the receiver is connected to a telephone jack connected to the local exchange telephone network. A remote control is provided to permit users to switch through on-screen menus to select programming and order pay-per-view broadcasts. The program signal is generated by a video information provider (VIP) or program provider which broadcasts the DSS program signal through a suitable directional antenna system to one or more satellites. The satellite or satellites rebroadcast the signal down to the user's antennas. From the antenna the signal is fed to the user's set top receiver which translates the DSS digital stream into an analog signal connected to the television set. The receiver is connected to the local exchange telephone network. In order to provide simultaneous reception of two different DSS channels in a single premise a set top receiver is required for each TV.
In the distribution of pay-per-view program selections utilizing addressable converters/decoders (set top receivers) at the customer's television the customer desiring to receive such a program most often utilizes the telephone network to order the desired selection from the TV vendor or VIP. The program signal is encrypted or enciphered and the customer or subscriber is permitted access by providing to the customer the appropriate key for deciphering or decryption. The set top receiver incorporates the deciphering or decryption equipment and deciphers the signal of a selected channel for the receiving equipment. The subscriber unit or receiver may also require the delivery of additional signaling before it can perform the deciphering.
The ordering of the program signal by a subscriber may be on an annual, monthly or shorter term basis. It may also be on a "per program" basis. A control unit at a remote location can supply the subscriber unit with a deciphering key for specific ordered programs. Systems of this type are described, for example, in the following U.S. Pat. No. 4,008,369 issued Feb. 15, 1977 to Theurer et al; U.S. Pat. No. 4,115,807 issued Sep. 19, 1978 to Pires; U.S. Pat. No. 4,325,078 issued Apr. 13, 1982 to Seaton et al.; U.S. Pat. No. 4,354,201 issued Oct. 12, 1982 to Secket et al. and U.S. Pat. No. 4,369,462 issued Jan 18, 1983 to Tomizawa et al.
U.S. Pat. No. 4,890,322 to Thomas L. Russell, Jr. describes a system which includes a mechanism for delivering deciphering key information before deciphering can proceed.
The Russell, Jr. patent discloses a system for providing per program ordering of television programs using announcement distribution service equipment present in many existing telephone networks. A program producer 12 supplies a program signal to a TV network 14 for dissemination. Broadcast stations 16 transmit the signal by airwaves, cable (CATV), direct broadcast satellite, or other appropriate carrier to subscriber receiver units 18. Although the subscriber receiver units may receive other TV signals for normal display, the program signals for the per-program ordering system are enciphered to prevent reception and display by unauthorized receiver units.
Auxiliary signals contained in the retrace interval of the television signal are used to provide program information and program ordering instructions. Before ordering a program, a subscriber tunes to the appropriate channel and reviews the program information. To order The program, the subscriber operates an automatic call button 38 on the receiver unit 18, within a time period specified in the displayed information. In response, the receiver unit automatically dials a number assigned to the announcement distribution service equipment 21 in the telephone network 20. The announcement distribution service equipment 21 recognizes from the particular number dialed that the incoming call requires a particular order response. The announcement distribution service equipment 21 then connects the call to an announcement in the form of a low speed voiceband data signal which contains a deciphering key.
The receiver unit 18 receives and demodulates the low speed voiceband data signal to recover the deciphering key and stores the key in a memory associated with the particular program channel. The receiver unit 18 utilizes the deciphering key to decode the broadcast signal of the selected program. A later broadcast program will require a different deciphering key.
Other patents describing the ordering and supplying of television programs are described in the following U.S. Patents: U.S. Pat. No. 4,897,867 issued Jan. 30, 1990 to Foster et al. for a Method of and an arrangement for forwarding a customer order; U.S. Pat. No. 4,763,191 issued Aug. 9, 1988 to Gordon et al. for Dial-up Telephone Network Equipment for Requesting an identified selection; and U.S. Pat. No. 4,797,913 issued Jan. 10, 1989 to Kaplan et al. for Direct Telephone Dial Ordering Service.